Technical description and composition of the LG RZ-27LZ55 TV, panel type and applicable modules. The composition of the modules.LG
Model: RZ-27LZ55
Chassis / Version: ML-041A
Panel: V270B1-L01
Inverter (backlight): V070-001 - 2714240027 - I270W1-24-V04-D1H2 - Rev.1H
Power Supply (PSU): 6871TPT275E
PWM Power: FA5501A (PFC), STR-T2268
MOSFET Power: 2SK3681
MainBoard: 6870TC29A18
IC MainBoard: IC1: VCT49X3F-F2, IC901: GM5221H-LF-BC, GM5221, MPS7720, FLI2300, LA7222, M12L64322A, SM5301BS
Tuner: TAEW-G053D
Technical Specifications RZ-27LZ55
LG RZ-27LZ55
General recommendations for repairing TV LCD
LG TV, made on the ML-041A chassis, like many other electronic devices, it is advisable to start repairing by inspecting all external and internal elements. Using visible changes in the state of components, it is usually possible to determine the further direction of troubleshooting and localization of the defect before the necessary measurements are taken. In some cases, faulty elements can be seen with the naked eye, for example, charred resistors or swollen metal-ceramic capacitors, or electrolytic in rectifier filters. Ring cracks formed in the soldered terminals of transformers or heating elements of the circuit are also frequent sources of many malfunctions with a variety of external manifestations.
If the RZ-27LZ55 TV does not turn on, does not make any sounds when it is turned on, and also no indicators on the front panel light or blink - there is a high probability of a malfunction in the power module. In some cases, only the stabilizer or power converter of the control processor may be malfunctioning, which is typical for some LG models. When diagnosing and repairing the power supply, after replacing the swollen capacitors of the secondary rectifier filters (if any), you must first check the mains fuse. When it is broken, the power elements of transistors and rectifier bridge diodes should be checked for avalanche (thermal) breakdown.
Power switches in switching power supplies (SMPS) fail extremely rarely for no reason and, if they are broken, it is necessary to look for a malfunction in the stabilization circuits by checking electrolytic capacitors, semiconductor devices, and resistors in the primary circuit. The cause may be a malfunction of the PWM controller chip, which can only be checked by replacing it with a new or obviously working one.
If the LG RZ-27LZ55 does not have an image, but there is sound and the TV is controlled from the remote control, a malfunction in the display backlight nodes is likely. The lamps or the power converter - inverter may be faulty. Often in such cases, when you turn on the TV, an image appears and immediately disappears. First of all, it is necessary to verify the operability of the electrolytic capacitors of the rectifier filter supplying the inverter, and check the LCD lamps by connecting external and obviously serviceable for diagnosis to the connectors. When disabling protection in order to enable the diagnosis of a malfunction, special care should be taken, and after completion of all repair work, it is necessary to restore the circuit and the inverter protection for further safe operation of the TV.
If it is not possible to replace the MB board (SSB), you need to check the health of its elements - VCT 49X3F F2 000 (ver 4.60) GM5221 MPS7720 FLI2300 LA7222 M12L64322A SM5301BS. Defective components should be replaced.
Remember! Attempts at self-repair by users of the LG RZ-27LZ55 TV without the appropriate qualifications and the necessary experience can lead to serious negative consequences!
Service manual / schematic diagram -------------> LG RZ-27LZ55 Chassis ML-041A
The appearance of MainBoard 6870TC29A18 is shown in the figure below:6870TC29A18
The appearance of the power supply
Main features of the device LG RZ-27LZ55:
Installed matrix (LCD panel) V270B1-L01.
To power the backlight used inverter V070-001.
The necessary supply voltages for all nodes of the TV LG RZ-27LZ55 are generated by the power supply module 6871TPT275E, or its analogs using microchips FA5501A (PFC), STR-T2268 and power switches of the type 2SK3681.
MainBoard - the main board (motherboard) is a 6870TC29A18 module, using IC1 chips: VCT49X3F-F2, IC901: GM5221H-LF-BC, GM5221, MPS7720, FLI2300, LA7222, M12L64322A, SM5301BS and others.
The TAEW-G053D tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: CMO
Model: V270B1-L01
Type: a-Si TFT-LCD, Panel
Diagonal size: 27.0 inch
Resolution: 1366x768, WXGA
Display Mode: Super MVA, Normally Black, Transmissive
Active Area: 596.259x335.232 mm
Surface: Antiglare, Hard coating (3H)
Brightness: 550 cd / m²
Contrast Ratio: 1000: 1
Display Colors: 16.7M (8-bit), CIE1931 75%
Response Time: 8 (G to G)
Frequency: 60Hz
Lamp Type: 14 pcs CCFL Embedded (Inverter)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 5.0V
